Glycoside hydrolase family 9
In molecular biology, glycoside hydrolase family 9 is a family of glycoside hydrolases.
Glycoside hydrolases are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycoside hydrolases, based on sequence similarity, has led to the definition of >100 different families. This classification is available on the CAZy web site, and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.
Glycoside hydrolase family 9 comprises enzymes with several known activities including endoglucanase and cellobiohydrolase. These enzymes were formerly known as cellulase family E. Cellulases catalyse the endohydrolysis of 1,4-beta-D-glucosidic linkages in cellulose. GH9 family members have also been found in green microalgae that show highest sequence identity to endogenous GH9 cellulases from invertebrate metazoans https://prosite.expasy.org/PDOC00511.
